External influences that can interfere with how a driver drives are all those things that are out of the car and can interfere with the way the driver drives, such as speed, reflexes and others.
Based on this, we can say that pedestrians very close to Tanya's car will be an external influence that will interfere with the way she drives. This is because to avoid hitting pedestrians Tanya will have to drive at a slower speed than she is used to.
